The present invention relates generally to data processing, and more particularly to management of a network to control data communications through the network.
It has become popular to provide a guaranteed data communication level through a particular data network. Termed “Quality of Service” (QoS), it is a guarantee that end-to-end quality characteristics of data communication, such as latency, data loss, etc., will not exceed a specified level. There is an increasing demand on current networks to deliver QoS for such applications as interactive video communication and high quality video distribution. QoS requires a network to allocate enough network resource (e.g., bandwidth capacity) end to end for the application. Multi Protocol Label Switching (MPLS) is one technique that allows dedicated paths to be set up across a core network to achieve QoS. MPLS gives each packet entering a network a label or identifier that contains information indicative of the destination. However, as a network grows, the number of MPLS paths will increase significantly (on the order of n2, where n is the number of paths). Since MPLS paths, and the resource of each path, are preassigned, increasing the number of nodes will tend to decrease the resource that can be allocated to each path, limiting the capacity of each path. (As used herein, “resource” is the data handling or communicating capability of a path.) Also, if the paths are created each time a request for a data transfer through the core network is made, the job of path creation would become huge, and the computing power at each node of the core network would need to be immense.
Another technique for QoS is to use a resource reservation protocol (RSVP). RSVP requires, however, that reservation and confirmation of the resource occur on every node through which the data will pass every time the connection is made. This, in turn, will tend to create long delays while a connection is being established. Also, RSVP suffers from the same problems as MPLS networks: as the network grows in size, the number of connections and the number of transactions for the reservation that a node must handle will also grow, and rapidly. Network growth, then, will require a computational power at each node for the connection process that is daunting. Network growth will tend to create a situation in which the network nodes are unable to handle the necessary connections and transactions. This makes RSVP difficult to scale in large networks.
Thus, there is a need for a scalable technique of providing QoS paths connections through a network.